I’m also a mouse (MX Master) and Trackpad devotee, I used both for navigation however have an extensive set of trackpad gestures mapped to actions with BetterTouchTool. I like that these gestures are available when I’m using my laptop away from my desk.
I also have my iPad Pro 12.9” to the left of my monitor using universal control. I find it far better to navigate the iPad with the Trackpad.
Some examples of my must have gestures.
Four finger swipe
left - window to left half of screen
right - window to right half of screen
up - maximize window
down - hide window (command h)
Tip tap two fingers
left - copy
right - paste
Double tap two fingers - resize window and centre on current screen (like a focus mode)
Double tap three fingers - resize window to other monitor and centre
Double tap four fingers - quit app that is running
Just a few 
However if I had to only use one, I’d get rid of the mouse at this point, it’s taken me many years to get to this position.